The present invention relates generally to the field of radio frequency (RF) reflector antennas.
FIGS. 1, 2A, and 2B illustrate a typical prior art reflector-type antenna system 100 comprising a main RF reflector antenna 102 and an RF sub-reflector 108, which is attached to the main reflector antenna 102 by support structures 112. As shown in FIG. 2A, the main reflector antenna 102 comprises an RF reflecting surface 104 that reflects an RF signal 202 between the main reflector 102 and the sub-reflector 108.
Referring to FIG. 1, an outgoing RF signal 202 is provided through an RF signal feed 110 to the sub-reflector 108, which reflects the RF signal 202 to the RF reflecting surface 104 of the main reflector 102. The main reflector 102 reflects the RF signal 202 away from the antenna system 100 (e.g., toward a remotely located receiving antenna (not shown)).
In incoming RF signal 202 travels a reverse direction. That is, an incoming RF signal 202 (e.g., from a remotely located transmitting antenna (not shown)) arrives at the antenna system 100 and is reflected from the RF reflecting surface 104 of the main reflector 102 to the sub-reflector 108, which reflects the RF signal 202 into the signal feed 110.
Typically, the RF reflecting surface 104 is curved to reflect the RF signal 202 to and from a focal area 210 (see FIGS. 2A and 2B) on the sub-reflector 108. The RF aperture 212 of the main reflector antenna 102 is related to its depth 216. The larger the aperture 212 the larger the depth 216. Thus, to increase the aperture 212 of a given antenna system 102, the depth 216 of the main reflector antenna 102 must be correspondingly increased.
Some embodiments of the present invention allow for an increased RF aperture of a reflector antenna system without a corresponding large increase in depth of the main reflector. This and other advantages can be provided by some embodiments of the invention.